SNL Researchers Design Microgrid for Artemis Lunar Base

Sandia National Laboratories (SNL) is one of three National Nuclear Security Administration research and development laboratories in the U.S. On May 5, SNL announced that its researchers are working in partnership with NASA to design a microgrid for the future Artemis lunar base.

 

An artist's depiction of a potential lunar base with a microgrid system. Image used courtesy of Eric Lundin/SNL

 

This project is funded by the Department of Energy’s Office of Electricity as part of a DOE-NASA partnership.

 

A Base Camp for Mars Exploration

The Artemis base will serve as a kind of testbed for technology and a base camp for the future exploration of Mars. The Artemis base will have a habitation unit with space for four astronauts. Using a process called in-situ resource utilization (ISRU), NASA intends for its space explorers to source materials from the nearby areas to generate products that allow for long-term habitation and deep space exploration. With this in mind, NASA intends to establish facilities for mining and fuel processing.

It is hoped that such facilities will provide astronauts with the ability to produce water, rocket fuel, oxygen, and other materials needed for extended lunar exploration. This would provide astronauts with greater self-sufficiency and reduce the need for cargo supplies to be brought to base from Earth.

 

Screenshot used courtesy of NASA

 

Although the mining and processing facilities will be located away from the base camp area, the two units will be connected via the electrical grid during emergencies. This can improve grid resiliency and robustness.

As part of the SNL/NASA partnership, SNL team member and electrical engineer, Lee Rashkin, and control engineer, Dave Wilson, is heading up the design of an electrical system controller for the mining and processing center microgrid. NASA is designing the electrical system controller for the habitation unit. According to another member of the SNL team, the system will be very similar to the International Space Station’s (ISS’s) direct-current electrical system. The SNL team is developing the system that will connect the two microgrids.

 

Designing a Lunar Energy Power Management System

Rashkin and Wilson are concentrating on designing a controller that can maintain an even voltage level across a variety of timescales. The SNL team members use the Secure Scalable Microgrid Testbed to analyze and modify their control system.

In a recent news release, Wilson commented, “The facility also has specialized energy storage emulators that can help us determine the specifications for how much energy storage the base needs and their requirements.”

By using three interconnected direct current (DC) microgrids and custom-built electronics, the testbed can mimic devices and power-production systems including diesel generators, photovoltaic arrays, energy storage emulators, and power converters.

Other researchers involved in the controller development include SNL computer scientist Marvin Cook, engineering professors at Michigan Technological University, Wayne Weaver and Rush Robinett III, and chief scientist of OptimoJoe, Joseph Young.

 

Building Microgrid Resiliency

Following controller design, the SNL team is looking at developing the system for connecting the mining facility and habitation unit microgrids. The SNL team needs to make the system flexible enough to be able to redirect power where and when needed. The system must also be oversized to ensure power supply should other components of the system fail.

In the same news release, an electrical engineer at SNL, Jack Flicker said, “Usually, we have some combination of those two, where it’s oversized to some extent, but you are also able to flexibly route power how you need to within a microgrid or between independent, yet cooperative microgrids like we’re exploring for the moon. Flicker added, “In a contingency event such as an energy storage system failing during an eclipse, we want to be able to port the power at the mining facility over to the base camp to keep astronauts safe.”

Other elements of the microgrid connection system that the SNL team will be exploring include the effect of distance between the mining facility and habitation unit on transfer efficiency and stability, optimal connection voltage, as well as alternating current (AC) conversion to DC.

 

SNL researchers use the DETL to conduct hardware-in-the-loop experiments. Image used courtesy of SNL

 

The SNL team will be using the Distributed Energy Technologies Laboratory (DETL) to conduct hardware-in-the-loop experiments. Such experiments can generate pre-field test simulations of different scenarios including catastrophic blackouts and changing weather conditions. 

The researchers will also use the Emera DC microgrid on Kirtland Air Force Base to observe how a power-electronic-heavy system can operate and port power in low-energy contingency scenarios.

 

Feature image used courtesy of Nicolas Thomas/Unsplash